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Temporal Resolution
 
The shortest time duration between two events that can be measured with an MRI experiment.
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Pediatric and Fetal MRI - Musculoskeletal and Joint MRI - DICOM - Coils - Resources - Contrast Enhanced MRI
 
Cardiac MRIForum -
related threads
 
In the last years, cardiac MRI techniques have progressively improved. No other noninvasive imaging modality provides the same degree of contrast and temporal resolution for the assessment of cardiovascular anatomy and pathology. Contraindications MRI are the same as for other magnetic resonance techniques.
The primary advantage of MRI is extremely high contrast resolution between different tissue types, including blood. Moreover, MRI is a true 3 dimensional imaging modality and images can be obtained in any oblique plane along the true cardiac axes while preserving high temporal and spatial resolution with precise demonstration of cardiac anatomy without the administration of contrast media.
Due to these properties, MRI can precisely characterize cardiac function and quantify cavity volumes, ejection fraction, and left ventricular mass. In addition, cardiac MRI has the ability to quantify flow (see flow quantification), including bulk flow in vessels, pressure gradients across stenosis, regurgitant fractions and shunt fractions. Valve morphology and area can be determined and the severity of stenosis quantified. In certain disease states, such as myocardial infarction, the contrast resolution of MRI is further improved by the addition of extrinsic contrast agents (see myocardial late enhancement).
A dedicated cardiac coil, and a field strength higher than 1 Tesla is recommended to have sufficient signal. Cardiac MRI acquires ECG gating. Cardiac gating (ECGs) obtained within the MRI scanner, can be degraded by the superimposed electrical potential of flowing blood in the magnetic field. Therefore, excellent contact between the skin and ECG leads is necessary. For male patients, the skin at the lead sites can be shaved. A good cooperation of the patient is necessary because breath holding at the end of expiration is practiced during the most sequences.

See also Displacement Encoding with Stimulated Echoes.
For Ultrasound Imaging (USI) see Cardiac Ultrasound at Medical-Ultrasound-Imaging.com.

See also the related poll results: 'In 2010 your scanner will probably work with a field strength of' and 'MRI will have replaced 50% of x-ray exams by'
 
Images, Movies, Sliders:
 Infarct 4 Chamber Cine  Open this link in a new window
    

Courtesy of  Robert R. Edelman
 MVP Parasternal  Open this link in a new window
    

Courtesy of  Robert R. Edelman
 Delayed Myocardial Contrast Enhancement from Infarct  Open this link in a new window
      

Courtesy of  Robert R. Edelman
 
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• View the DATABASE results for 'Cardiac MRI' (15).Open this link in a new window


• View the NEWS results for 'Cardiac MRI' (15).Open this link in a new window.
 
Further Reading:
  Basics:
Cardiac MRI - Technical Aspects Primer
Wednesday, 7 August 2002
Prediction of Myocardial Viability by MRI
1999   by circ.ahajournals.org    
  News & More:
MRI technology visualizes heart metabolism in real time
Friday, 18 November 2022   by medicalxpress.com    
Even early forms of liver disease affect heart health, Cedars-Sinai study finds
Thursday, 8 December 2022   by www.eurekalert.org    
MRI sheds light on COVID vaccine-associated heart muscle injury
Tuesday, 15 February 2022   by www.sciencedaily.com    
Radiologists must master cardiac CT, MRI to keep pace with demand: The heart is not a magical organ
Monday, 1 March 2021   by www.radiologybusiness.com    
Diffusion weighted imaging (DWI) and diffusion tensor imaging (DTI) in the heart (myocardium)
Sunday, 30 August 2020   by github.com    
Non-invasive diagnostic procedures for suspected CHD: Search reveals informative evidence
Wednesday, 8 July 2020   by medicalxpress.co    
Cardiac MRI Becoming More Widely Available Thanks to AI and Reduced Exam Times
Wednesday, 19 February 2020   by www.dicardiology.com    
Controlling patient's breathing makes cardiac MRI more accurate
Friday, 13 May 2016   by www.upi.com    
Precise visualization of myocardial injury: World's first patient-based cardiac MRI study using 7T MRI
Wednesday, 10 February 2016   by medicalxpress.com    
New technique could allow for safer, more accurate heart scans
Thursday, 10 December 2015   by www.gizmag.com    
MRI Resources 
Online Books - Non-English - Sequences - Pregnancy - Knee MRI - Safety Products
 
Contrast Enhanced MRIInfoSheet: - Contrast Agents - 
Intro, Overview, 
Characteristics, 
Types of, 
etc.MRI Resource Directory:
 - Contrast Enhanced MRI -
 
Contrast enhanced MRI is a commonly used procedure in magnetic resonance imaging. The need to more accurately characterize different types of lesions and to detect all malignant lesions is the main reason for the use of intravenous contrast agents.
Some methods are available to improve the contrast of different tissues. The focus of dynamic contrast enhanced MRI (DCE-MRI) is on contrast kinetics with demands for spatial resolution dependent on the application. DCE-MR imaging is used for diagnosis of cancer (see also liver imaging, abdominal imaging, breast MRI, dynamic scanning) as well as for diagnosis of cardiac infarction (see perfusion imaging, cardiac MRI). Quantitative DCE-MRI requires special data acquisition techniques and analysis software.
Contrast enhanced magnetic resonance angiography (CE-MRA) allows the visualization of vessels and the temporal resolution provides a separation of arteries and veins. These methods share the need for acquisition methods with high temporal and spatial resolution.
Double contrast administration (combined contrast enhanced (CCE) MRI) uses two contrast agents with complementary mechanisms e.g., superparamagnetic iron oxide to darken the background liver and gadolinium to brighten the vessels. A variety of different categories of contrast agents are currently available for clinical use.
Reasons for the use of contrast agents in MRI scans are:
Relaxation characteristics of normal and pathologic tissues are not always different enough to produce obvious differences in signal intensity.
Pathology that is sometimes occult on unenhanced images becomes obvious in the presence of contrast.
Enhancement significantly increases MRI sensitivity.
In addition to improving delineation between normal and abnormal tissues, the pattern of contrast enhancement can improve diagnostic specificity by facilitating characterization of the lesion(s) in question.
Contrast can yield physiologic and functional information in addition to lesion delineation.
Imaging of arteries and veins with contrast enhanced angiography (CE MRA).

Common Indications:
Brain MRI : Preoperative/pretreatment evaluation and postoperative evaluation of brain tumor therapy, CNS infections, noninfectious inflammatory disease and meningeal disease.
Spine MRI : Infection/inflammatory disease, primary tumors, drop metastases, initial evaluation of syrinx, postoperative evaluation of the lumbar spine: disk vs. scar.
Breast MRI : Detection of breast cancer in case of dense breasts, implants, malignant lymph nodes, or scarring after treatment for breast cancer, diagnosis of a suspicious breast lesion in order to avoid biopsy.

For Ultrasound Imaging (USI) see Contrast Enhanced Ultrasound at Medical-Ultrasound-Imaging.com. See also Blood Pool Agents, Myocardial Late Enhancement, Cardiovascular Imaging, Contrast Enhanced MR Venography, Contrast Resolution, Dynamic Scanning, Lung Imaging, Hepatobiliary Contrast Agents, Contrast Medium and MRI Guided Biopsy.
 
Images, Movies, Sliders:
 Delayed Myocardial Contrast Enhancement from Infarct  Open this link in a new window
      

Courtesy of  Robert R. Edelman
 Left Circumflex Ischemia First-pass Contrast Enhancement  Open this link in a new window
      

Courtesy of  Robert R. Edelman

 Normal Lung Gd Perfusion MRI  Open this link in a new window
 MRI of the Brain Stem with Temoral Bone and Auditory System  Open this link in a new window
    
SlidersSliders Overview

 Breast MRI Images T1 Pre - Post Contrast  Open this link in a new window
 
Radiology-tip.comradContrast Enhanced Computed Tomography
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Medical-Ultrasound-Imaging.comContrast Enhanced Ultrasound,  Contrast Enhanced Doppler Imaging
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• View the DATABASE results for 'Contrast Enhanced MRI' (14).Open this link in a new window


• View the NEWS results for 'Contrast Enhanced MRI' (8).Open this link in a new window.
 
Further Reading:
  Basics:
Optimal k-Space Sampling for Dynamic Contrast-Enhanced MRI with an Application to MR Renography
Thursday, 5 November 2009   by www.ncbi.nlm.nih.gov    
  News & More:
FDA Approves Gadopiclenol for Contrast-Enhanced Magnetic Resonance Imaging
Tuesday, 27 September 2022   by www.pharmacytimes.com    
Effect of gadolinium-based contrast agent on breast diffusion-tensor imaging
Thursday, 6 August 2020   by www.eurekalert.org    
Artificial Intelligence Processes Provide Solutions to Gadolinium Retention Concerns
Thursday, 30 January 2020   by www.itnonline.com    
Accuracy of Unenhanced MRI in the Detection of New Brain Lesions in Multiple Sclerosis
Tuesday, 12 March 2019   by pubs.rsna.org    
The Effects of Breathing Motion on DCE-MRI Images: Phantom Studies Simulating Respiratory Motion to Compare CAIPIRINHA-VIBE, Radial-VIBE, and Conventional VIBE
Tuesday, 7 February 2017   by www.kjronline.org    
Novel Imaging Technique Improves Prostate Cancer Detection
Tuesday, 6 January 2015   by health.ucsd.edu    
New oxygen-enhanced MRI scan 'helps identify most dangerous tumours'
Thursday, 10 December 2015   by www.dailymail.co.uk    
All-organic MRI Contrast Agent Tested In Mice
Monday, 24 September 2012   by cen.acs.org    
A groundbreaking new graphene-based MRI contrast agent
Friday, 8 June 2012   by www.nanowerk.com    
Searchterm 'temporal' was also found in the following services: 
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Magnet Stability
 
Temporal stability of the magnetic field. Factors to be considered are field decay of superconducting magnets in persistent mode, aging of permanent magnet material, temperature dependence of permanent magnet material, and temporal stability of magnet power supplies.
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Further Reading:
  Basics:
What affects the strength of a magnet?
   by my.execpc.com    
  News & More:
Superconducting Magnets
   by hyperphysics.phy-astr.gsu.edu    
MRI Resources 
Mass Spectrometry - Manufacturers - Colonography - Movies - Education - Homepages
 
Perfusion ImagingForum -
related threadsInfoSheet: - Sequences - 
Intro, 
Overview, 
Types of, 
etc.
 
(PWI - Perfusion Weighted Imaging) Perfusion MRI techniques (e.g. PRESTO - Principles of Echo Shifting using a Train of Observations) are sensitive to microscopic levels of blood flow. Contrast enhanced relative cerebral blood volume (rCBV) is the most used perfusion imaging. Both, the ready availability and the T2* susceptibility effects of gadolinium, rather than the T1 shortening effects make gadolinium a suitable agent for use in perfusion imaging. Susceptibility here refers to the loss of MR signal, most marked on T2* (gradient echo)-weighted and T2 (spin echo)-weighted sequences, caused by the magnetic field-distorting effects of paramagnetic substances.
T2* perfusion uses dynamic sequences based on multi or single shot techniques. The T2* (T2) MRI signal drop within or across a brain region is caused by spin dephasing during the rapid passage of contrast agent through the capillary bed. The signal decrease is used to compute the relative perfusion to that region. The bolus through the tissue is only a few seconds, high temporal resolution imaging is required to obtain sequential images during the wash in and wash out of the contrast material and therefore, resolve the first pass of the tracer. Due to the high temporal resolution, processing and calculation of hemodynamic maps are available (including mean transit time (MTT), time to peak (TTP), time of arrival (T0), negative integral (N1) and index.
An important neuroradiological indication for MRI is the evaluation of incipient or acute stroke via perfusion and diffusion imaging. Diffusion imaging can demonstrate the central effect of a stroke on the brain, whereas perfusion imaging visualizes the larger 'second ring' delineating blood flow and blood volume. Qualitative and in some instances quantitative (e.g. quantitative imaging of perfusion using a single subtraction) maps of regional organ perfusion can thus be obtained.
Echo planar and potentially echo volume techniques together with appropriate computing power offer real time images of dynamic variations in water characteristics reflecting perfusion, diffusion, oxygenation (see also Oxygen Mapping) and flow.
Another type of perfusion MR imaging allows the evaluation of myocardial ischemia during pharmacologic stress. After e.g., adenosine infusion, multiple short axis views (see cardiac axes) of the heart are obtained during the administration of gadolinium contrast. Ischemic areas show up as areas of delayed and diminished enhancement. The MRI stress perfusion has been shown to be more accurate than nuclear SPECT exams. Myocardial late enhancement and stress perfusion imaging can also be performed during the same cardiac MRI examination.
 
Images, Movies, Sliders:
 Normal Lung Gd Perfusion MRI  Open this link in a new window
      

Courtesy of  Robert R. Edelman

 Left Circumflex Ischemia First-pass Contrast Enhancement  Open this link in a new window
 
Radiology-tip.comradPerfusion Scintigraphy
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Medical-Ultrasound-Imaging.comBolus Injection
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• View the DATABASE results for 'Perfusion Imaging' (16).Open this link in a new window


• View the NEWS results for 'Perfusion Imaging' (3).Open this link in a new window.
 
Further Reading:
  Basics:
CHAPTER 55: Ischemia
2003
EVALUATION OF HUMAN STROKE BY MR IMAGING
2000
  News & More:
Non-invasive diagnostic procedures for suspected CHD: Search reveals informative evidence
Wednesday, 8 July 2020   by medicalxpress.co    
Implementation of Dual-Source RF Excitation in 3 T MR-Scanners Allows for Nearly Identical ADC Values Compared to 1.5 T MR Scanners in the Abdomen
Wednesday, 29 February 2012   by www.plosone.org    
Motion-compensation of Cardiac Perfusion MRI using a Statistical Texture Ensemble(.pdf)
June 2003   by www.imm.dtu.dk    
Turbo-FLASH Based Arterial Spin Labeled Perfusion MRI at 7 T
Thursday, 20 June 2013   by www.plosone.org    
Measuring Cerebral Blood Flow Using Magnetic Resonance Imaging Techniques
1999   by www.stanford.edu    
Vascular Filters of Functional MRI: Spatial Localization Using BOLD and CBV Contrast
MRI Resources 
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